[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Deinocheirus



Jaime Headden wrote (on _Deinocheirus_):
>The scapula and coracoid point at the [oviraptorosaurs], [...]
        In what way?

[ornithimimosaurs and oviraptorsaurs)
>when considering that the two groups are pretty close to each 
>other anyway, in a sister-clade relationship-like way,
        Interesting... is your source on this Sereno 1997?

>not unlike allosaurs and metriacanthosaurs [sinraptorids].
        Considering that _Metriacanthosaurus_ is not well known at this time
(although it appears to share one synapomorphy with Allosauridae proper), I
would encourage you to use the officially named taxon Sinraptoridae.

>but the forearm still looks a lot like oviraptorosaurs to be too 
>close for comfort. Ah well, nothing's easy.
        I am afraid I simply do not know enough about the subject to tell
this myself. Are these similarities derived?

>So, we get convergence in this dinosaur, [...]
        I'll try to contain my shock. :)
        
>On a project with some theropods (allosaurians to be exact) that I'll be 
>posting soon, I've run into the chance of making proportionate ratios, 
>and one of these is a humerus-to-neck ratio.
        As many workers have commented on, ratios really aren't always all
that useful. They may help to quantify a general observation ("arms greater
than 75% of dorsal vertebral column length" works better than "long arms").
However, allometry, changes in proportions during ontogeny due to
differential growth, can really mess with ratios. There are statistical
methods designed to "filter" allometry, if you will. Unfortunately, they are
not as accessable as ratios. 
        Just thought I'd point this out, in case somebody doesn't seem all
that impressed with whatever ratios you come up with.

        Wagner
----------------------------------------------------------------------------
    Jonathan R. Wagner, Dept. of Geosciences, TTU, Lubbock, TX 79409-1053
        "Why does the universe hate me?" - G'Kar